RE: ASM rebalancing

From: <Jay.Miller_at_tdameritrade.com>
Date: Thu, 21 May 2015 13:46:53 +0000
Message-ID: <0D8F4CAC0F9D3C4AACC63F50FD9957F728E232C8_at_PRDCTWPEMLMB31.prod-am.ameritrade.com>

Hot spot rebalancing was part of the Oracle marketing presentation just before ASM came out. Someone must have eventually convinced the marketing department it didn’t do that because they stopped talking about it.

Jay Miller
Sr. Oracle DBA
201.369.8355

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Chris Taylor Sent: Wednesday, May 20, 2015 12:15 PM
To: lawrence.malcolm_at_gmail.com
Cc: oracle-l-freelists
Subject: Re: ASM rebalancing

For some reason, many of us (myself included) used to think ASM moved hot blocks to different areas to smooth out performance. This was a myth but I'm unsure of the origin. I know it started many years ago however and I was disabused of the notion some time ago.

The only rebalancing ASM does is when you add or remove disks and data has to be moved/rebalanced based on percentages used of each device in the disk group. Has nothing to do with block usage.

Regards,
Chris

On Wed, May 20, 2015 at 11:00 AM, Malcolm Lawrence <lawrence.malcolm_at_gmail.com<mailto:lawrence.malcolm_at_gmail.com>> wrote: All,

Does ASM move hot spots around in the background, or do you have to do a rebalance accomplish that?

I cannot find anywhere in Oracle documentation stating that it does, so I assume that that it does not.

Malcolm Lawrence

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Received on Thu May 21 2015 - 15:46:53 CEST